Cost-effectiveness analysis of bicycle helmet subsidies in a defined population

Abstract

Objective: To examine the potential effects of bicycle safety helmet cost subsidy on bicycle head injury rates and costs.

Design: Using empiric data on the incidence and costs of bicycle injuries to children, we examined the hypothetical effects of various bicycle helmet subsidies in a cost-effectiveness analysis. A hypothetical cohort of 100,000 5- through 9-year-olds was followed for 5 years after helmet cost subsidization. Sensitivity analyses were done of three different levels of safety helmet subsidy ($5, $10, $15), three discount rates (2%, 4%, 6%), 10 levels of safety helmet use ranging from 10% to 100%, and the occurrence or nonoccurrence of catastrophic head injuries.

Patients: Forty-three children 5 through 9 years of age and 27 children 10 through 14 years of age with head injuries due to bicycling were identified through emergency department surveillance of a population of 29,533.

Setting: Group Health Cooperative of Puget Sound, a large health maintenance organization.

Outcome measures: Bicycle head injuries prevented and the savings or costs associated with various subsidy, safety helmet use, and discount rates.

Results: Hypothetically, an increase in bicycle helmet use rates to 40% to 50% due to subsidies of $5 or $10 prevents 564 to 840 head injuries in a cohort of 100,000 5- through 9-year-olds over 5 years. Under these conditions and a 2% discount rate, cost savings ranging from $189,207 to $427,808 will result when catastrophic head injuries are included in the analysis.

Conclusion: Subsidization of bicycle safety helmets to achieve a cost of $14 to $20 per helmet and use rates of 40% to 50% will likely prove cost-effective. Empirical evidence from a Seattle campaign suggests that such helmet use rates are achievable.